Originally posted by wolfsoul
I have a question; Why is it that Draino is so incredibly corrosive that it can wipe out all that is clogging your drain, and yet it manages to stay in the thin plastic bottle?
chemistry! Cincy's Mom might be able to verify this but here's my stab at an answer:

When Draino interacts with the water, a chemical change occurs -- it "melts" (maybe attacks/loosens is a better word) the goop and the water flushes it away. I remember creating a version of draino in chemistry but darned if I can remember what ingredients were used-- dish soap was one.